This invention relates to an electromagnetic device.
Electromagnetic devices such as transformers or chokes typically comprise one or more conductive windings for electric current and a magnetic frame, usually referred to as a core, in which magnetic flux due to current in the windings is concentrated.
In order to increase the operating efficiency of such devices, particularly transformers, it has become commonplace to use specially formulated ferro-magnetic strip material shaped in the form of a toroidal core, with conductive windings disposed helically around the core.
While the length of the magnetic flux path in the core of such a transformer will be long relative to the effective length of the portion of the windings inducing magnetic flux, such transformers are relatively efficient and have a very low radiated magnetic fluid.
In high power applications, for example, in transformers which are used in electrical substations or in other power distribution systems, heat dissipation within the core and windings of the transformer may be problematic, and such large transformers are usually oil cooled. This, of course, increases the cost and complexity of the transformer.